Prongs PI
by MadlySaneCatLady
Summary: James is not a very good detective. He knows Sirius and Remus are up to something, but he just can't find out what. Remus & Sirius slash. :) Rated eventual M-ish.
1. Greenhouse 3

They were hiding something, James knew it. He watched with narrowed eyes as Remus and Sirius snuck away from the castle and across the grounds from the dormitory window. His two friends had been sneaking around for a while now, and James wanted to know what they were up to. Without him! He frowned as the two boys rounded the turret opposite Gryffindor tower. He was determined to get to the bottom of this.

Not bothering with his invisibility cloak, James conjured a rope and fastened it tightly to one of the massive and heavy four-poster beds and prepared to complete a climb he had done many times before he had gotten his cloak. This would be much faster than sneaking through the castle – he'd have a much better chance of finding out what Sirius and Remus were up to at this hour of the night.

His feet touched the ground and he took a moment to look around before deciding it would be faster and less risky to travel the grounds as a stag rather than a student out after hours. The transformation was brief and simple to him now after two years' practice and soon he was trotting purposefully across the grounds, following the path he had seen his best friends take earlier.

As he rounded the castle, he heard the sound of Sirius laughing and Remus reprimanding him quietly from behind Greenhouse Three. He approached more slowly, doing his best to not make any noise. He figured it might be best to revert into human form, as James made far less noise than Prongs. Unfortunately, he lost his footing in the transition from four legs to two and snapped a twig under his foot as he attempted to keep upright.

'Shh,' he heard Remus shush Sirius quietly. 'Someone's coming!'

'I'll say,' Sirius whispered back with a hearty chuckle.

'Shut up!' Remus whispered hoarsely as James rounded the corner to find them both sitting on the grass facing the greenhouse.

'Prongs!' Sirius grinned easily. 'What brings you out and about at this hour?'

'I came down here to ask you the same question,' James said dejectedly. 'Why are you two sneaking off in the middle of the night without me?'

'Sirius asked me for help with understanding some of our Herbology homework,' Remus told him smoothly. 'After a while trying to bash information into Sirius' head, I figured it might be best to just show him what I was trying to explain.'

James looked to Sirius who grinned sheepishly. He eyed Sirius' sweater on the ground and the way Remus' shirt collar was askew. 'Uh huh,' he pointed to the sweater. 'Why are you stripping then?'

'What, it's warm out,' Sirius shrugged. 'And all these plants just get me so hot and bothered, you know?'

James snorted. 'Whatever, Padfoot.' He narrowed his eyes. 'Don't go sneaking around without me again. You might get into trouble, and that'd be unfair.'

Remus rolled his eyes. 'Of course, James, we'll be sure to go get you next time we decide to do our homework. There's ample room for misbehaving and trouble there.'

'Well, now we're all out and about together, you want to get up to some mischief?' James asked, grinning expectantly at his best friend.

He saw a flash of annoyance cross Sirius' face before he shook his head. 'Nah, I actually do need to finish this homework. I put it off too long. I'm not out in the middle of the night looking at plants because I like them, Prongs.'

'Suit yourselves,' James shrugged and turned away. 'I'll try and save you some sweets from the kitchens for when you're finished.'

'Cheers mate,' Sirius called after him. 'Now, where were we, Moony?'

'We were looking at the difference between the leaves of the Mandrake and the leaves of the Snapping Lotus.'

As James made his way back up the rope and into the dormitory, he thought, not unreasonably, that Sirius and Remus had not been truthful with him when he had found them. It seemed extremely unlikely that Sirius would put this much effort into any sort of homework… although, as James thought about it, it _was_ likely that Remus would force him into doing some more hands-on research just to make sure he actually learned something for once. That was a very Remus thing to do.

James shrugged and went to grab his invisibility cloak. Maybe Sirius and Remus were being uncooperative, but he knew the house elves in the kitchen were always happy to do whatever he asked.


	2. Potions

James had put the incident with the greenhouse out of his mind until one potions class a little over a week later. He was a little late for class, having taken the time to ambush Snape on his way through the dungeons. He sauntered in, knowing Slughorn wouldn't _dream_ of telling off one of his star pupils for being a few minutes late. Unfortunately, he frowned, as Snape entered after him with just as little fanfare from Slughorn, Snape was also a star pupil. Someday, James just wanted Snape to walk in just a little _too_ late, or a little too dishevelled and just have Slughorn throw a bloody little tantrum at him. He'd seen Slughorn throw tantrums several times before, usually when Peter had blown something up. He didn't think it was too farfetched an idea.

His frown evaporated when he saw Sirius and Remus chuckling to themselves, obviously, he assumed, about what they were sure was an incredible ambush James had pulled off on Snape. He grinned easily at them and made his way over to their usual table in the back of the room.

'So, tonight then?' Sirius was whispering as James approached. James' grin faltered, it seemed that they hadn't even noticed him yet.

Remus was looking very flushed as he nodded. He looked up, his eyes going wide. 'Oh, hey James,' he said, slightly too loudly.

'Prongs!' Sirius' head whipped up. 'You made it! We were worried Snivellus got you.'

'More like the other way around,' James smirked.

'Nice,' Sirius grinned appreciatively. 'Levicorpus again?'

'Nah, I summoned his pants right off his arse,' James chuckled. 'Felt bad after though… some poor first year girls had to see _that_.'

'Cruel,' Remus shook his head.

'Oh Moony, don't I know it,' James sighed dramatically. 'Those poor girls and their poor virginal eyes. It's a good thing you weren't there, Moony, your eyes needn't be sullied.'

'Immature arse,' Remus threw his book at him.

'So catty,' James tutted. 'Why Remus, if I didn't know any better, I'd think it was _that time of the month_.' He wagged his eyebrows mischievously.

Remus rolled his eyes and bent to pick up his book. Sirius wolf whistled at his backside as he did so. 'Ugh, grow up, the pair of you.'

'Never Moony, darling,' Sirius did a fairly good aristocratic impression. He clicked his tongue. 'Besides, you _do_ have a fantastically wondrous _derriere_.'

'Gotta love your deadpan abilities, mate,' James laughed appreciatively. 'So,' he added in an undertone as Slughorn began a lecture about the many properties of love potions with a pointed look in their direction. 'What were you two planning when I got here?'

'Huh?' Remus looked at him quizzically. 'What are you on about? We weren't planning anything.'

'He said 'tonight then?' when I was coming over here,' James nodded towards Sirius. 'What're you guys up to?' he eyed them beadily. 'Are you planning something without me?'

'What? No!' Sirius shook his head sharply. 'Mooney's just going to help me with some potions stuff. I'm not nearly as good as you two… and like I've always said, Moony's destined to be a teacher.'

Remus' cheeks turned a delicate shade of pink. 'Shut up, Sirius. They'd never let me teach.'

'Of course they would,' James smiled at his friend fondly. 'Hell, the kids you teach might actually _learn_ something.'

'And I'd be so jealous,' Sirius added. 'You'd be a fun teacher. Not, y'know, boring or creepy.'

'Or boring _and_ creepy,' James gestured in Slughorn's direction with his head. The three boys descended into a fit of snorts and snickers, but James kept a watchful eye on his two friends, wondering just what they had been talking about before Remus had noticed him. James had a sneaking suspicion it had nothing to do with potions tutoring.

He was going to find out what they were hiding. He was more determined than ever.

'What are you doing?' Peter asked James, coming into the common room late after a particularly traumatic detention with McGonagall to find James huddled up in an armchair by the dying fire with his nose buried in the Map.

'Moony and Padfoot are up to something,' James muttered, not moving his eyes' attention from the Map. 'They keep sneaking around at all hours of the night and I want to know what they're up to.' He finally looked up at his friend in time to see the last traces of mirth leave his eyes. 'What?'

Peter shook his head. 'Did you ever think maybe they don't want you to know? Or, better yet, maybe that _you_ don't want to know?'

'Oh, I want to know,' James said immediately. 'I _need_ to know. Wait a minute, do _you_ know what they're up to?'

Peter sighed. 'No, but I don't have the burning curiosity you're plagued with, either. Looks like I've finally found what I'm better at in this group.' With a final smirk, Peter left the common room and made his way up the stairs to the boys' dormitory, leaving James alone with the Map and the final glowing embers in the fireplace.

James looked down at the Map again and frowned. Remus and Sirius' dots hadn't moved at all since they'd declared an early night and gone up to bed, even though James had heard them making their plans in Potions.

He yawned widely. It looked to him like they weren't going anywhere tonight. He figured he may as well go to bed and find out what they were up to another night.

James awoke the next morning, Saturday morning, to the sun creeping under his eyelids. He groaned. He hadn't shut the curtains so he would better hear if Remus and Sirius had decided to go out for another late night romp around the grounds without him.

'Shut up Prongs,' Sirius grumbled, sounding rather closer than he usually did, in response to James' groan. 'Close the curtains and go back to sleep.'

James opened his eyes and looked to his left. 'What are you doing in Moony's bed?'

'Ssh, you're gonna wake him up!' Sirius reprimanded in a whisper. 'He kept bitching he was cold last night – I was tired of hearing it. Padfoot has very warm fur, y'know.'

'I always said you're more useful as a dog,' James nodded.

'That's nice,' Sirius closed his eyes again and snuggled closer to Remus for warmth. 'Now shut up and go back to sleep or get the hell out.'

James pulled the curtain facing the window shut and closed his eyes again. It wasn't long before Sirius was snoring once again and James wondered to himself why Remus would rather have a perfect imitation of Nearly-Headless Nick's saw band sleeping next to him than be a little cold at night. He supposed Padfoot didn't snore so much with his canine snout. Sirius truly was a lot more agreeable as a dog, it seemed. With a snort at that thought, James fell back asleep.


	3. Hogsmeade

'Are you even paying attention, Potter?' Lily demanded, tearing James' attention away from the window and back on his date. 'Honestly, you spend all this time wearing me down, and I finally go out with you and by date three you're already ignoring me.'

'Sorry Lily,' James said, genuinely sorry his attention was not with her. 'I've just got something on my mind.'

'I'll say,' Lily raised her gingery eyebrows. 'You've been squinting out the window all afternoon. What's going on James?' she asked more kindly, catching James' hand over the table in Madam Puddifoot's Tea Shop, where she had dragged him for what she had hoped would be a _proper_ date for a change.

'Sorry, no, it's nothing,' James shook his head. 'I'm just being stupid.'

'James, you're always being stupid, and that's never taken up so much of your attention before,' Lily rolled her eyes. 'What's the problem? Maybe I can help.'

'No, it's just-' James broke off as he caught sight of Sirius and Remus walking down the street together towards the Three Broomsticks. Sirius ushered Remus in through the door with a whack to Remus' backside. Remus threw a disapproving look over his shoulder before cracking a smile. James felt his eyes narrow. What were they doing out? They had told James they were going to study back in the common room and skip Hogsmeade this weekend.

'Does this have something to do with Sirius and Remus?' Lily was watching him closely.

'They're up to something,' James sighed. 'And, I'm going to sound like a four year old, but I don't like being left out of whatever it is they're up to.'

'Well, your life is changing, isn't it?' Lily said reasonably after a moment's pause. 'You and I are dating now – I don't see them clambering to join us on our dates, do you? You can't be jealous of them having a closer relationship now that we have ours.'

'It's not the same thing,' James frowned.

'Hmm,' Lily shrugged noncommittally. She watched him for a minute as he glared out the window and sighed. 'Do you want to go there?'

James shook himself. 'No, sorry, I'm ruining our date. I'm being stupid, you're right, as always.'

Lily smiled. 'And don't you ever forget it.'

'It's really nice out,' Lily commented as they walked towards the castle together, hand-in-hand.

'Yeah, hard to believe it's almost Hallowe'en,' James smiled at her. 'Speaking of, is Slughorn still on about his stupid party?'

'Yes, and yes you still have to come with me,' Lily rolled her eyes. 'Stop trying to get out of it. I am _not_ suffering through his idea of a fun time alone.'

'Damn, I thought you'd show me _some_ pity and say I don't have to,' James grinned at her as she whacked him gently in the back of the head. 'Oh come on, Lils, what kind of man would I be if I made you go suffer through Slughorn alone?'

'Not a very good one,' Lily bumped his shoulder with her own. They passed the window of the Three Broomsticks and Lily smiled. 'Look, Remus and Sirius are still there. Do you want to say hello?'

James looked in through the window at his two friends. They sat on the same side of the table with a book open, Sirius leaning into Remus as he looked at whatever Remus was showing him on the page. James smiled; perhaps this would be the time he'd find out what they were up to without him all the time. 'Sure,' he led the way to the door, opening it for Lily.

'Why, thank you, what a gentlemen,' Lily shot him a wink as she walked in. James took a moment to admire her backside before following her inside.

'Mm, Moony you smell nice,' Sirius was saying as Lily and James approached. 'Like chocolate and peppermint… and Moony.'

'Shush,' Remus flushed nearly purple as he looked around him to see if anyone had heard. 'Oh! James, Lily, nice to see you!' he said loudly, looking spooked.

'Hi,' Lily smiled. 'Are we interrupting?'

'Just studying,' Sirius rolled his eyes. 'Moony's got teaching in his blood. I swear he could make History of Magic interesting. Actually, now I think of it, he _does_.'

Remus rolled his eyes. 'You just say that so I keep helping you.' He turned to James and Lily. 'So, how's your date going?'

'Shockingly well, given it's with this idiot,' Lily smirked.

'Hey, I've been a perfect gentleman all day,' James protested. He smiled at Remus and Sirius. 'So you two decided to come out this weekend after all?'

'Yeah, I convinced Moony that a change of scenery would help me retain more facts,' Sirius smirked. 'The Butterbeer's just a bonus.'

'This is a muggle book,' James frowned at the copy of _Pride and Prejudice_ on the table. 'You weren't studying,' he accused. 'Were you planning something without me again?'

'It's for Sirius' Muggle Studies class,' Remus shook his head. 'The assignment is to read a muggle book to better understand their culture. Goodness, you've been very suspicious lately, James. What's going on?'

'You guys are always sneaking around,' James huffed. 'You're hiding something.'

'And you're getting paranoid, mate,' Sirius furrowed his brow. 'You should get some more sleep, man. It's starting to get to you.'

'James, you're our friend,' Remus said quietly. 'We'd never leave you out of anything important. You know that right?'

James eyed the shadow in Remus' eyes that told him his friend was lying. He sighed, knowing he would get nothing out of pushing the issue further here. 'You're right. I'm sorry.'

'Did you want to join us?' Sirius asked politely. 'We could take a break.'

'Oh, no, no,' Lily smiled. 'You get back to your studies. James and I were going to sit by the lake.'

'Have fun, you two,' Remus smiled as they turned away. 'Now, Sirius, where were we?'

'You were giving me _terribly naughty_ ideas,' Sirius snickered.

James frowned as Lily led him outside and back towards the castle. He was now more certain than ever that his friends were up to something secretive. And he was more determined ever to find out what.


	4. Not Hiding

'Will you stop worrying about what they're up to?' Lily reprimanded as James stared out the library window, looking down at the table near the lake where Sirius and Remus sat together, both looking completely engrossed in the book Remus was holding. Well, really, as James looked on, _Remus_ was thoroughly engrossed in the book; Sirius looked far more interested in Remus. James figured Remus was probably reading aloud; it was the only way Remus _ever_ got Sirius to read.

'James,' Peter whined from the table he and Lily were sitting at, Lily attempting to help Peter grasp even the basics of potions. 'You _promised_ you'd help me.'

'And what am I, chopped liver?' Lily frowned.

'She's right, mate,' James turned back to them, leaning against the window sill. 'She's the potions whiz, not me – be nice. Keep in mind she's only helping out of the goodness of her heart. She can probably change her mind about this whole helping you thing. I'd change my mind pretty quickly after her, too.'

James eyes Peter's horrified expression and smirked, shooting a wink at Lily. 'Oh, c'mon Pete, you're my mate. Do you really think I'd let you fail Slughorn's class just to watch him throw a bloody little tantrum over you, actually, you know what, that sounds like a lot of fun.'

' _Jaaaames_ ,' Peter whined again.

'I know, I know,' James rolled his eyes and flopped himself into the chair next to Peter. He's always liked Peter, they were friends after all, but he was finding a new appreciation for his friend as he began to feel more and more excluded from whatever Remus and Sirius were up to without him. At least Peter was always honest with him. He never had to guess at what Peter was thinking – it was usually about how cool his friends were, but all the same, he never hid that fact from his friends.

James felt his attention drifting back towards the window and the two boys he knew were sitting together outside. Together. _Without him._

'What's wrong, James?' Peter asked quietly, eyeing his friend with concern. 'You look sad.'

'Oh, he's just being a jealous prat,' Lily tutted. 'He think Remus and Sirius are up to something without him and deliberately keeping him out of it.'

'Are you still on about that?' Peter asked incredulously. 'I _told_ you to just drop it, mate. Seriously, if they had anything big to tell you, they'd tell you.'

'You know, don't you?' James accused.

'I know they hang around each other a lot more,' Peter shrugged. 'Do you blame them, though? I'm taking all sorts of remedial classes, so I'm never around. You and Lily are spending a lot more time together… it's normal.'

James deflated in his seat. 'Stop making sense, Pete. It's weird for me. You're never the wise, logical one.'

'Well, neither are you,' Lily supplied fondly.

'That's really reserved for Remus,' Peter shrugged. 'And on _extremely_ rare occasions, Sirius.'

'Extremely,' James repeated with a nod. As Lily continued on with her explanation, James allowed himself to drift away with his thoughts once again. Was Peter really right? Perheps the two other boys really _were_ just getting closer in his and Peter's absence. The thought cheered him slightly. He stood up to stretch and caught sight of Remus dragging Sirius across the grounds towards the castle by the forearm. It looked like Sirius was at least up to something. And if Remus was _this_ upset about it, James knew he wanted to be involved. He resolved to ask his best friend later how he could help.

James made his way up to the boys' dormitory a few hours later to find it empty. He popped open his trunk and tossed his books inside, taking a moment to stretch. Teaching Peter was exhausting, but, he reasoned, more rewarding than teaching other people. Peter was very forthcoming with his gratitude. James liked being showered with affection. He couldn't help it, it was just how he was.

'Completely irresponsible,' Remus' voice preceded him and Sirius into the room. Both boys walked in looking dishevelled and soaked.

'What happened to you two?' James raised an eyebrow.

'This stupid, bloody git decided it would be _really_ funny to coax me onto a broomstick and then crash it into the bleeding lake!' Remus steamed.

'I didn't crash on purpose, you berk,' Sirius retorted, looking just as upset. 'Like I wanted to be all cold and soggy.'

Remus' expression softened at the pouty look on Sirius' face. He huffed out a sigh. 'I know, I know. Come on, warm baths. That's what's needed here.'

'How do you do that?' James wondered aloud, shaking his head at the way Sirius was always able to calm Remus, even in the heat of a full tirade.

'Do what?' both boys asked at the same time.

'How do calm Remus down like that all the time Sirius?' James clarified. 'I don't think I've ever seen you two fight for any extended period of time.'

'It's just my animal magnetism,' Sirius winked. 'I'm just _that_ charming, y'know?'

Remus rolled his eyes. 'Come on, you idiot. I'm freezing and _really_ want to wash all this lake gunk out of my hair.'

'I'll wash it out for you,' Sirius wagged his eyebrows suggestively. 'I can wash _all of it_ for you, if you catch my drift.'

James snorted. 'Practicing flirting, are you?'

'I'm always in perfect form, thank you,' Sirius smirked. 'C'mon, Moony. Let's go get that gunk out of your hair.'

James watched them go pensively. Perhaps Lily and Peter had been right. It really did look like his two friends were simply getting closer in the others' absence. James felt a sense of relief wash over him. He was certainly glad they weren't keeping anything from him.


End file.
